Share 'Brake Chatter - Help!'

Hello,   Raced my Kuota Kross for the first time this weekend.  Love the bike except for some pretty serious brake chatter.  I'm running the stock carbon forks, Avid Ultimates and Easton Circuit rims.  The brake cable is hung from the bottom stacker on the head tube.  No brake hole on the fork to hang it off the fork.   Any suggestions on how to calm the chatter down?   Thanks all!   Jimi Surf